package network;

import java.io.IOException;
import java.net.*;
import java.util.Scanner;

/**
 * Created with IntelliJ IDEA.
 * Description:客户端
 * User:DELL
 * Date:2025-02-26
 * Time:16:10
 */
public class UdpEchoClient {
    private DatagramSocket socket=null;
    private String serverIp="";
    private int serverPort=0;
    public UdpEchoClient(String ip,int port) throws SocketException {
        //创建这个对象不能手动指定端口
        socket=new DatagramSocket();
        //由于UDP自身不会持有对端的信息，就需要在应用程序里把对端的情况给记录下来。
        //这里咱们主要记录对端的ip和端口
        serverIp=ip;
        serverPort=port;
    }
    public void start() throws IOException {
        System.out.println("客户端启动！");
        Scanner scanner=new Scanner(System.in);
        while (true){
            //1.从控制台读取数据作为请求
            System.out.println("->");
            String request=scanner.next();
            //2.把请求内容构造成DatagramPacket对象，发给服务器
            DatagramPacket requestPacket=new DatagramPacket(request.getBytes(),request.getBytes().length,
                    InetAddress.getByName(serverIp),serverPort);
            socket.send(requestPacket);
            //3.尝试读取服务器返回的响应
            DatagramPacket responsePacket=new DatagramPacket(new byte[4096],4096);
            socket.receive(responsePacket);
            //4.把响应，转换成字符串，并显示出来
            String response=new String(responsePacket.getData(),0,responsePacket.getLength());
            System.out.println(response);
        }
    }

    public static void main(String[] args) throws IOException {
        UdpEchoClient client=new UdpEchoClient("127.0.0.1",9595);
        client.start();
    }
}
